310 



THE GEOLOGIST. 



The Agecroft section was about half a mile to the north-west of the Pen- 

 dleton one. The same fossil fish remains, and the Anthracoptera 

 JBrowniana of Salter, are met with in the impure cannel, black bass, and 

 ironstone of both mines, although in much less abundance at the former 

 than the latter. 



Now at St. George's Colliery, Manchester, about 2\ miles in a straight 

 line from Pendleton Colliery, the following is a section of the strata im- 

 mediately above the four-feet coal : — 



Rock Bauds . . . 

 Hard Gray Rock . 

 Coal, called Nine Inches 

 Black Sod, Rotten 

 Impure Cannel Coal . 

 Four-eeet Mine 



yds. ft. 

 3 2 



Not only is there a great difference in the nature of the deposits, but 

 there is an equal difference in their fossil organic remains, few, if any, of 

 the fishes being met with at Bradford which were. so abundant at Pendle- 

 ton. Until the sinking of the Patricroft pit by Messrs. Lancaster, and 

 the proving of the Pendleton four-feet coal there, it was not easy to be 

 convinced that the Bradford and Pendleton seams were the same ; but 

 when the author saw the red ironstone at Patricroft, he immediately iden- 

 tified it with a similar bed seen on the banks of the Medlock, below the 

 brewery in Beswick. Now the last-named instance lies 366 yards above 

 the four-feet coal of Bradford, as can be proved in the river section of 

 the Medlock, between Beswick and the old ford across the river, just be- 

 low the iron bridge near Philip's Park, where the " four-feet " outcrops. 

 The distance is 1100 yards, and the dip of the strata, on an average, 1 in 

 3 ; so that will give 366 yards between the two strata. At Patricroft, the 

 distance in the sinking between the four-feet coal and the red ironstone 

 was 378 yards. From this, 20 yards has to be deducted for the dip of the 

 strata, leaving 358 yards as the thickness ; so one seam is within 10 yards' 

 distance of the other, — no great variance in 5 or 6 miles. 



By looking at the map it will be seen that the Trias covers the upper 

 coal-field on its dip at Ardwick, and no traces of the Permian beds, which 

 are known to be found under the south-east of the city, are shown at the 

 surface. There is little doubt but that both the Trias and Permian beds 

 rest unconformably on the upper coal-measures here, but they cannot be 

 seen. Some time since, Mr. Mellor was so kind as to show him a soft red 

 sand without pebbles, very like the Yauxhall sand, which had been met 

 with in driving a tunnel to the dip of the Ardwick limestones. At first 

 he was inclined to consider this sand as Permian, but he has since come 

 to the conclusion that it is Trias, as no Permian marls are found above it. 

 He had given, he said, twenty-five years to investigate the geology of 

 Manchester, and the two maps, imperfect as they were, are the result of his 

 labours. Younger geologists must take them in hand and improve upon 

 them. There was plenty of work to be done before the geology of the 

 district, six miles around the Manchester Exchange, would be all well 

 known and correctly laid down. He hoped that the structure of the 

 ground upon which the city stood would attract the attention of the 

 members. 



Mr. E. Hull said it was an excellent local map, and conveyed a A ery 

 proper and correct notion of the general structure and principal features 

 of the district of Manchester. He took a different view from Mr. Binney 



